DE2823612A1 - PROCESS AND EQUIPMENT FOR CARGO BEAM WELDING - Google Patents

Description

The present invention relates to a method for charge carrier beam welding, in particular electron beam welding, as well as a Facility for carrying out such a procedure.

When a workpiece of considerable thickness, such as 50 mm and larger, to be welded with a charged beam such as an electron beam, one of the most difficult problems is to prevent that the material melted by the beam flows out of the welding zone.

From DE-OS 22 04 187 it is known when welding a vertical Seam with a horizontally running electron beam on the beam entry side and a shoe-like weld pool support device on the jet exit side to arrange that when welding with the beam

809850/0834 " ² -

is moved along the joint to be welded. The Assumption assumed that the surface of the weld pool is a few millimeters below the beam cross-section and therefore the can arrange shoe-like weld pool support device so far below the beam that it is not damaged by the beam, but can still support the melt.

This well-known principle fails when welding a horizontal joint with a horizontal beam and for larger workpiece thicknesses, since the condition here is that the melt is sufficiently far below the beam cross-section is practically no longer adhered to.

The present invention is based on the object of specifying measures that prevent the melt from flowing out of a beam with a charge carrier Prevent welded workpiece, especially when welding horizontally with a horizontal beam and / or when welding thick workpieces.

This object is achieved according to the invention by the method according to patent claim 1 solved.

The subclaims relate to further developments and advantageous configurations of the method according to the invention and preferred devices for carrying out the method according to the invention.

An important feature of the invention is that the charge carrier beam, which runs along a beam path extending into the workpiece, on or in the vicinity of a surface of the Workpiece is deflected in such a way that the direction of the deflected beam is closer to the vertically upward direction runs as the direction of the beam before the deflection. In other words, is supposed to be the angle that is needed to get one into the To rotate the arrow pointing in the direction of the deflected beam in the direction pointing vertically upwards, must be smaller than the angle required to rotate an arrow pointing in the direction of the beam prior to deflection in the vertically upward direction.

809850/0834

(The turning always takes place in the sense in which the desired transition can be achieved with the smallest change in angle). The deflection area can be seen in the direction of propagation of the beam in front of the relevant workpiece surface or the workpiece surface in question or are located behind the workpiece surface in question and the area can be, for example, 15 or 30 mm or also extend a little more away from the workpiece surface.

The beam can be slightly downwards with respect to the horizontal be directed towards the surface of the workpiece in an inclined direction, e.g. at an angle of -10 to -85 ° with respect to the horizontal, in particular between -25 and -60 °, and the beam is then at the beam entry side of the workpiece is deflected, for example, in a substantially horizontal direction. The part of the The beam path can contain a part inclined downward with respect to the horizontal and / or an upwardly inclined part with respect to the horizontal can for the most part run obliquely downwards or obliquely upwards, preferably everything with angles that are at most about 10 to 20 ° with respect to the horizontal. When the beam penetrates the workpiece and exits it at a beam exit surface, the Beam preferably deflected upwards in the vicinity of this beam exit surface. In this case, if desired, on the beam exit side an arrangement for welding pool support must be provided, which contains, for example, a particulate material, and at the The beam entry side can also have a sweatband support device ("Shoe") may be provided in order to prevent the melt from flowing out of the welding area. Because of the deflection of the beam the sweatband support devices can be arranged on the workpiece in such a way that they are not damaged by the beam and still enter Ensure perfect retention of the melt. The shoe or tub type sweatband support device or devices preferably migrate with the beam along the seam when welding a seam horizontally.

In another embodiment of the invention, the beam is at the Beam entry side of the workpiece and / or within the workpiece

809850/0834

and / or magnetically deflected on the beam exit side of the workpiece. These measures can be taken individually and in any combination with one another and possibly in conjunction with an inclined downward can be used extending on the workpiece beam, the inclination of the beam is at least 5 ° with respect to the horizontal. As mentioned, the beam can also be directed essentially vertically onto the workpiece and in the vicinity of the beam exit side be deflected in a substantially horizontal direction.

In the following, exemplary embodiments of the invention are referred to explained in more detail on the drawing.

Show it:

Figure 1 is a vertical sectional view of a workpiece with a horizontal beam moving from bottom to top with respect to the workpiece and with a known weld pool support device you can see;

Figure 2 is a vertical sectional view of a workpiece with a Method and a device according to an embodiment of the invention is welded; the welding direction (direction the relative movement between the beam and the workpiece) is horizontal here;

FIG. 3 shows a view of the arrangement according to FIG. 2 from above;

FIG. 4 is a somewhat enlarged vertical section corresponding to FIG. 2 in a plane IV-IV of FIG. 3 with the sectional planes V-V for FIG. 5, VI-VI for FIG. 6 and VII-VII for FIG. 7;

FIG. 5 shows a sectional view in a plane V-V of FIG. 4 in the jet plane through the molten bath;

FIG. 6 shows a sectional view in a plane VI-VI of FIG. 4, in which the beam, the weld pool, a joint to be welded and a weld bead are shown; 809850/0834

FIG. 7 is a perspective sectional view of the weld pool support device in a section plane VII-VII of FIG. 4; the melt is omitted to form the trough-shaped Shape of a ceramic insert of the weld pool support device to make visible;

FIG. 8 is a side view of the weld pool support device;

Figure 9 is a schematic vertical section through a workpiece during welding a vertically running joint with a beam running essentially horizontally in the workpiece, which is deflected according to an embodiment of the method according to the invention;

FIG. 10 is a view similar to FIG. 9, additionally showing the feed is shown by additional material;

FIG. 11 is a partial perspective view of a magnetic deflection device, as used to deflect the beam on the beam entry side or the beam exit side of a workpiece Can be found;

FIG. 12 shows a schematic cross section in a plane XII-XII of FIG Fig. 11;

FIG. 13 shows a view corresponding to FIG. 9, in which additional electrodes and a circuit for controlling the position of the beam path are shown; the welding direction is for example horizontal;

FIG. 14A shows a vertical section of a workpiece in which the path of a Electrode beam and pole pieces for deflecting the beam are shown; the welding direction is here again as accepted vertically;

809850/0834

FIG. 14B is a view corresponding to FIG. 14A, in which the distribution of the magnetic field in the direction of propagation of the beam is shown;

FIG. 15 shows an end view in a direction XV-XV of FIG. 14A;

FIG. 16 shows a sectional view of the beam entry side of a workpiece and a trough-like weld pool support device arranged thereon as well as a magnetic field through which the beam used for welding of a relative steep downward path just before the jet entry side into a substantially horizontal path Way is diverted;

FIG. 17 is a perspective arrangement of a weld pool support device attention and an arrangement for generating a magnetic deflection field corresponding to FIG. 16;

Figure 18 is a side view of a magnetic deflector and Weld pool support device on the beam entry side of the workpiece;

FIG. 19 is a horizontal section of a somewhat modified compared to FIG Embodiment; the cutting plane corresponds to the plane IXX-IXX in FIG. 18;

FIG. 20 is a plan view of a workpiece with a gap between two by an electron beam to be welded workpiece part and a schematically illustrated magnetic deflection device;

FIG. 21 shows a schematic sectional view in a plane XXI-XXI of FIG. 20;

FIG. 22 shows a vertical section in a plane XXII-XXII of FIG. 20;

809850 / Θ834

FIGS. 23 and 24 are views corresponding to FIGS. 21 and 22 of a modification the deflection device according to FIGS. 20 to 22;

FIG. 25 shows in the direction of propagation of an electron beam Seen plan view of pole pieces of a device for waving the beam in a "perpendicular to the welding joint trending direction;

FIG. 26 shows a vertical section in a plane XXVI-XXVI of FIG. 25; FIG. 27 shows a sectional view in a plane XXVII-XXVII of FIG. 25;

FIGS. 28 and 29 are views corresponding to FIGS. 25 and 26, respectively, of a modification of the magnetic deflection device according to FIG Figures 25 to 27.

Since electron welding is currently the most common type of charge carrier beam welding, at least as far as workpieces of considerable thickness are involved, the invention is described below with reference to Electron beam welding explained. The term "beam path" is used when the beam is essentially related to the beam generating system is stationary mean the central axis of the beam or if the beam periodically reciprocates with respect to the weld area will (wag), the time mean of the central beam axis. Workpieces of considerable thickness, e.g. 50 mm or more and workpieces, in which the joint to be welded is irregular or has larger dimensions, e.g. 1 mm or more, are generally known to be welded with a waved beam.

Figure 1 shows a workpiece assembly 10, e.g. Welding metal! plates with a horizontally running Electron beam 14 are welded. The beam forms a metal melt 12 in the workpiece, which is directed vertically downwards Movement (arrow 16) of the workpiece with respect to the beam moves along the butt joint and forms the weld seam when it solidifies.

809850/0834

To prevent the melt from flowing out of the weld area, A trough-like weld pool support device is located on a beam entry side 52 and on a beam exit side 54 of the workpiece 18 and 20 respectively, for which the term "shoe" is to be used in the following. When the seam is welded, they migrate both shoes 18, 20 with the jet 14 along the parting line.

Obviously, the top edges of shoes 18 and 20 must be below of the beam cross-section 14, otherwise the shoes would be damaged by the beam. The known weld seam support device can therefore be bad for the horizontal welding of a parting line that is essentially in a horizontal plane, and should not be used for welding thick workpieces, as in these cases the molten workpiece material tends to run over the The edges of the shoes flow.

According to the present invention, this problem can be avoided by the fact that the beam 14, as shown in Fig. 2, is deflected at or shortly before the beam entry surface 52. So it initially runs along a sloping downward one Path from above into a trough-like depression of a weld pool support shoe 18 moving with the beam along the workpiece, and the beam then becomes in the plane in an upward direction the parting line or weld seam deflected.

The beam, as shown in FIG. 2, can be inside the workpiece is inclined slightly downwards; the workpiece is then arranged in this case that the butt joint lies in a plane which forms an angle of, for example, 10 ° with respect to the horizontal. The beam can be waved across the butt joint, as shown schematically is indicated by a double arrow 22. Since the beam 14 now enters the tub-like shoe from above, it can be on the beam entry side be arranged so high that an outflow of the melt from the weld area is prevented with certainty, without the. There is a risk that the shoe will be hit by the jet and damaged. A weld pool support device can be installed on the beam exit side 24 be arranged when the beam completely penetrates the workpiece

809850/0834

and partially exits at the back. This rear weld pool support device can consist of a rail open to the workpiece with a U-shaped cross-section, which is particulate material, such as a metal granulate 28 is filled. The walls of the rail 26 are preferably perforated so that vapors and gases can escape rearward from the welding area. Such a weld pool support is of course not required if the beam energy is chosen so that the penetration depth of the beam is smaller than the thickness of the workpiece, as indicated by a dashed line 23.

The inclination of the beam (with respect to the horizontal) and the distance of the edge of the shoe from the surface of the workpiece on the beam entry side are coordinated in such a way that the jet is no longer obstructed by the shoe (Fig. 2).

The shoe 30 forms a trough-like depression or trough 38, whose shape of the main flow direction of the melt flowing out of the weld area is adapted so that the out of the In the beam entry area, melt ejected from the workpiece is deflected back into the weld pool in an arc at a distance from the beam (see Fig. 5) and so fills the welding area again. This effect is supported by gravity (see Fig. 2) and prevents voids from occurring in the weld. The arcuate shape of the wall of the trough 38 facing away from the weld pool can be seen particularly in FIG.

If the melt expelled from the workpiece in the above-described Way is to be returned to the weld seam area, the temperature of the melt is allowed to come into contact with the shoe must not be reduced too much and this in turn must not be damaged by the hot melt. To this end a "weld pool support area" A (Fig. 6) of the shoe is designed in such a way that it can assume a sufficient temperature (this can if desired by intermittent exposure to the jet or with a part of the beam cross-section supported) and / or

809850/0834

the tub in the weld pool support area is made of a material low thermal conductivity, e.g. through a ceramic insert 32 or a ceramic lining. On the other hand, the melt must be in a "cooling section B" of the shoe that moves with the jet solidified at least on the surface and an upper weld bead of suitable shape formed. In this section the shoe must be well cooled and have sufficient thermal conductivity so that the melt during molding to a Weld bead of the desired shape can cool and solidify. Since the volume of the metal decreases in the course of solidification, the relative movement between the shoe and the workpiece does not with special needs.

The trough 38 is delimited by side walls 44 and a front wall 46. These walls are higher than the level of the melt. The cooling section A contains a cooling chamber, which through lines 36 into a coolant circuit is switched on. The side of the trough facing the beam entry surface 52 of the workpiece is open and the shoe can there provided with a sealing device such as a groove containing a packing or string of asbestos fibers and the like. The cooling section In the surface opposite the workpiece, B has a groove-like or groove-like depression with, for example, an approximately semicircular Cross section which can taper from the end adjacent to section A to the end facing away from this section. This slit-like Depression 40 acts like a strangus shape for forming the upper weld bead 42.

The shoe 18 is attached to a support 34 relative to the beam generation system 15 (Fig. 2) rests. The trough-like shape of the ceramic insert 32 can be seen particularly well in FIG. The side of the trough facing away from the workpiece is, as FIG. 5 shows, curved around the Flow of the melt coming from the area of the weld pool struck by the beam is driven out to lead back into the welding area. The bottom of the trough preferably rises from the open side towards the front wall 46.

809850/0834

-TT-

Generally speaking, the beam can be near the beam entry side 52 and / or in the vicinity of the beam exit side 54 are deflected. As Fig. 9 shows, the beam can so in a obliquely downward part 14a of the beam path is the workpiece approach, are deflected in the area of the beam entry side 52, so that the part of the beam path running in the workpiece runs approximately horizontally. In the workpiece, the beam can also run somewhat obliquely downwards or obliquely upwards or concave essentially everywhere be curved at the top. At the beam exit side 54, the beam 54 is then preferably a second time in an inclined upward direction Part 14c of the beam path deflected (Fig. 9).

If the beam area of a surface of the workpiece is deflected in such a way that the path of the beam after the Deflection forms a smaller angle with the vertically upward direction than the direction of the beam before the deflection, the point at which the beam penetrates the workpiece surface is higher than the adjacent part of the beam that is within of the workpiece. This makes attaching a weld pool support device considerably facilitates or in some cases even the use of such a weld pool support device superfluous at all.

As shown schematically in FIG. 10, the inclination of the molten Metal to flow out of the welding zone be reduced that you have an additional or filler material in the form of a metal rod or wire on the beam entrance side and / or the Introduces the jet exit side into the melt. The additional material cools the melt down a little so that it no longer flows so easily, and also prevents the melt from flowing out mechanically and via surface tension.

The deflection of the beam can be done by magnetic deflectors take place as shown in FIGS. 11 and 12. The deflector 58 includes a magnet yoke 59 made of magnetically soft material and a surrounding solenoid coil 60, which when excited by a Direct current generates a magnetic flux which exits at pole pieces 62 of the magnetic yoke. The pole pieces 62 are at or near the surface of the

809850 / Θ83Α

Workpiece arranged on opposite sides of the weld zone or parting line 50, so that a magnetic flux distribution 64 arises, which causes the beam deflection. The beam can enter the vertical beam surface from above at an angle of approximately 45 ° and is caused by the magnetic field 64 in the area of the beam entrance surface, preferably also slightly within the workpiece, e.g. deflected in the horizontal direction. In the case of non-magnetic workpiece material, the magnetic field penetrates or is penetrated into the workpiece a ferromagnetic workpiece material passed through this to the parting line. When exiting, the beam is then deflected upwards again, so that it is, for example, at an angle of, for example 45 ° to the beam exit surface exits upwards.

The position of the beam path within the workpiece can be determined by a Arrangement of the type shown in Fig. 13 can be controlled. The one shown in FIG. 13 is used to determine the beam position Embodiment two sets of electrodes si, s2 and S1, S2. The electrodes of each pair are on both sides of the target beam path and the two pairs are spaced apart in the direction of the desired beam path. In the example shown, a horizontal parting line is welded by means of a horizontal beam and the electrodes can be in in this case horizontally extending tungsten wires or rods. The electrode beam 14 is at the beam entry and the beam exit side deflected by a magnetic field 66 or 68, which is generated by a deflection device 58a or 58b.

As the deflection field 66 weakens, the beam path drifts away from the Position 14 '(solid line) to position 14 "(dashed line), so that the beam current picked up by the electrode si increases and the the beam current absorbed by the electrode s2 decreases. The signals generated by electrodes si and s2 become the input terminals a differential amplifier 59a which generates a first error signal which controls the deflection current in the deflector 58a. In many cases this regulation is sufficient, since the deflection angle. is not so essential on the beam exit side.

809850/0834

-B-

When the deflection field 68 on the beam exit side becomes weaker, the beam path shifts from position 14 '"(dash-dotted line) to position 14" "(multiple dash-dotted line). The deflection field 66 is preferably controlled with a short time constant, so that the beam with respect to the electrodes si and s2 remains essentially centered. While the beam current absorbed by the electrode si becomes greater than that of the electrode s2 absorbed beam current. The signals generated at electrodes S1 and S2 are fed to a further differential amplifier 59b, which sends a second error signal to regulate the (beam exit side) Deflecting device 58b in the sense of an extensive reduction in the beam current difference regulates. The time constant of the differential amplifier 59b containing control loop is made much larger, e.g. by at least an order of magnitude than that of the control loop containing the differential amplifier 59a, so that no control oscillations can enter.

Figure 14A is a vertical cross-section through a weld and a Butt joint 50 between two workpiece parts and shows the path of an electron beam 14, which is deflected upwards by an angle of, for example, 20 ° by the deflection field shown in FIG. 14B. The electron beam can have an acceleration voltage of about 150 kV and the deflection field a value of about 200 Gauss, which corresponds to a Electromagnets of about 4000 ampere turns can be generated. The field can be generated with a deflection device of the type shown in FIG Kind are generated whose pole pieces 62 on opposite sides the joint 50 rest on the jet entry surface. When the joint 50 has a width of about 3 mm, and the workpiece parts delimiting the joint are made of ferromagnetic material, so that they, so to speak Forming continuations of the pole pieces, as is shown schematically in FIG. 15, results approximately in that shown in FIG. 14B Field distribution. In such a case, the melt pool generated by the deflected beam can then be about 5 to 50 mm below it of the point at which the jet enters the joint between the workpiece parts.

809850 / D83A

-44-

In FIGS. 16 and 17, the use of a magnetic deflector 68 is that illustrated in connection with FIGS. 11 and 12 Art shown in connection with a weld pool support shoe 18 'which can be constructed essentially as it is has been described in connection with FIGS. 2 to 5. The width W of the shoe 18 'is, however, kept relatively small here, so that the distance between the pole pieces 62 does not become too great and the magnetic field required for the deflection is more easily generated can be. By deflecting the jet, the shoe 18 'can easily be designed in such a way that the melt is prevented from flowing out, without the shoe obstructing the jet. In the case of FIGS. 16 and 17, the deflection takes place essentially in front of the beam entry surface, so that the beam enters the workpiece practically horizontally. One of the pole pieces 62 can, as FIG. 17 shows, a section for the upper weld bead 42.

Figure 18 is an end view of a workpiece with a horizontal Butt joint is shown which is welded with an electron beam 14 which is deflected by an electromagnetic deflector 58 ' which corresponds essentially to that of FIGS. 11 and 12. However, the pole pieces 62 'are approximately semicircular here at their front ends cut out to accommodate a bundle of metal wires 74 to prevent the melt from flowing out of the weld area prevented. Another possibility, which is shown in dashed lines in FIG. 18 and in the horizontal section according to FIG. 19, is to a particulate weld pool support material to the weld area 72 via a channel or a chute 70, at least at the end adjacent to the jet entry side is open at the top, so that the beam is not obstructed by the walls of the channel 70.

The embodiments according to FIGS. 16 to 19 are particularly suitable for welding workpieces made of ferromagnetic material, like steel, since the beam is deflected shortly before entering the workpiece and therefore no penetration of the magnetic field into the workpiece is required.

8098SO / 6834

If desired, the beam on the beam exit side can be similar Wise be deflected and the weld pool can be supported in a similar manner as it was described above with regard to the beam entrance side.

The weld pool backing material 72 and the material of the wires 74 is preferably non-magnetic and may, for example, be made of non-magnetic stainless steel.

The beam deflection according to the invention can also be carried out with advantage during welding with a beam running essentially vertically downwards, as is shown in FIGS. 20 to 22. As is known, at least about 20 % of the beam current must exit the beam exit side of the workpiece in order to produce a flawless rear weld bead. This is known to make the use of mechanical weld pool support devices very difficult since any solid weld pool support material, such as a backing plate, will be welded to the workpiece.

According to the invention can also be used when welding with vertical Beam facilitate the attachment of a weld pool support device and / or the tendency of the melt to move out of the weld area flow out, thereby reducing that the beam shortly before leaving the workpiece at the beam exit side 54 in the plane the weld seam is deflected in such a way that it emerges as tangentially as possible from the beam exit side, as shown in FIG. FIG. 20 shows a plan view of the upper beam entry side of the workpiece and FIG. 21 shows the parting line 50 between the workpiece parts to be welded and one on the beam exit side 54 of the workpiece arranged electromagnetic deflection device 58, which generates a magnetic deflection field 68 'that the beam in the distracts the way you want. With regard to the distribution of the magnetic field shown in Figures 20 and 21, it was assumed that the workpiece is made of a non-ferromagnetic material.

8098ΒΟ / Θ834

-Tfr- '

Figure 21 shows that the magnetic deflection field is considerable Can extend into the workpiece, so that the beam in the middle of the workpiece in an undesirable manner is distracted. According to FIGS. 23 and 24, this can be avoided by an additional magnetic field 68 ″ which is polarized in opposite directions like deflection field 68 '. The compensating magnetic field 68 ″ is generated by an additional electromagnetic device 58a, the is also arranged on the beam exit side and has a magnet yoke, the legs of which enclose the deflector 58 ″. As can be seen from FIG. 23, the magnetic field 68 ″ in the workpiece does not drop as quickly as the actual deflection field 68 ′, so that it can compensate for the parts of the deflection field that extend further into the workpiece. The beam path thus runs essentially vertically, as shown in FIG. 24, until the uncompensated part of the which is directly effective at the beam exit surface 54 Deflection field 68 occurs. The deflection field 68 'is polarized so that the Beam 14 is deflected in the direction of the not yet welded joint 50.

The welding operation described in connection with FIGS The area of the jet exit surface 54 alone or in addition "wags", i.e. periodically moved back and forth. The direction of this Waviness can be transverse and / or along the weld seam or joint 50 take place and be synchronized with a conventional waviness of the beam in order to increase the amplitude of the waviness in the area of the beam exit side. If desired, the beam can in the area of the jet exit side, also independently from a conventional fronding or the only fronding be.

The waving of the beam on the beam exit side 54 of the workpiece can be done by an electromagnetic deflection device, as shown schematically in Figures 25, 26 and 27, the Represent views corresponding to FIGS. 20, 21 and 22, respectively. For waving the beam 14 in a direction running transversely to the joint 50 Thus, a magnetic deflection device 80 can be provided which

809850/0834

contains two pairs of pole pieces 82 and 84 that form a magnetic yoke 86 belong, which can then be fed by a coil 88 with an alternating current of a frequency of, for example, between 25 and 1000 Hz. The excitation of the pole pieces takes place in such a way that the pole pieces of each pair 82 or 84 have opposite polarities at a given moment, while the pole pieces of the two pairs, which are opposite one another on opposite sides of the joint 50 or the weld seam have the same polarity at any given moment have, as represented by the symbols N and S for a first point in time and (S) and (N) for a second point in time, in which the polarity of the exciting current has changed.

Figures 28 and 29 show an electromagnetic deflector for waving the beam in a direction 90 transverse to the separation step 50 and in a direction 92 in a direction along the parting line 50 or the weld seam 42. This device contains the deflection device 25 to 27 and an additional electromagnetic device comprising a magnetic yoke 90 which has pole pieces 92 and is excited by a coil 94 which is supplied with an alternating current of suitable frequency and phase with respect to the alternating current energizing the coil 88.

The magnetic deflectors discussed above with reference to FIG Figures 25 to 29 have been described, serve only for Wedflung of the beam, but not for the deflection which occurs by the deflecting device 58 "or the deflecting device 58", 58a, as referred to above on Figures 20 to 24 has been described.

809850 / 033A

Claims (20)

Claims (1 ./Method for welding a workpiece with a charge carrier beam, in particular an electron beam that moves along a the workpiece extending beam path, characterized in that the beam (14) in the immediate vicinity of a surface of the workpiece (10) penetrated by it is deflected in such a way that the direction of the deflected beam is closer to the vertically upward direction than the direction of the beam before the deflection. 2. The method according to claim 1, characterized in that that the beam (14) along a part (14a) of the beam path which is inclined downwards with respect to the horizontal onto a beam entry surface (52) of the workpiece is directed and is deflected in the vicinity of the beam entry surface (52) in the direction of the horizontal (Fig. 3, 4 and 9), 809850/0834 OFWQINAL INSPECTED -Z- 3. The method according to claim 1 or 2, dadurc h gekennzeich net that the beam is deflected on both sides of the surface in question. 4. The method according to claim 1 or 2, characterized marked It is calculated that the beam is deflected just before it penetrates the workpiece (Fig. 16). 5. The method of claim 1, 2, 3 or 4, characterized ζ ei chnet that the beam in the vicinity of a Beam exit surface (54) in an upward direction (14c) is deflected (Fig. '9). 6. The method according to claim 1, characterized in that that the beam along a substantially perpendicular downward part of the beam path onto the Workpiece is directed and deflected in the vicinity of the beam exit surface in the direction of the horizontal (Fig. 22). 7. The method according to claim 6, characterized in that that the deflection in the plane of a joint (50) to be welded and in the direction of one has not yet welded Part of the joint is deflected. 8. The method according to at least one of the preceding claims, characterized in that a weld pool support device (18, 26) is arranged on the beam entry and / or exit surface (52 or 54), which prevents the melt from flowing out of the weld area. 809850/0834 9. The method according to claim 8, characterized in that that the weld pool support device is moved with the beam with respect to the workpiece. 10. Device for performing the method according to claim 1, with a device containing a beam generating system, which delivers a beam of accelerated charge carriers extending along a beam path into a workpiece, characterized in that with a surface (52 and / or 54) penetrated by the beam (14) a deflection device (58) is arranged on the workpiece (10). 11. Device according to claim 10, characterized in that that the deflection device (58) is designed and arranged so that the beam within a distance range deflected by 30 mm from the surface. 12. Device according to claim 10 or 11, characterized ζ e i c h η e t that the device delivering the beam is inclined downwards onto a beam entry side of the workpiece directed beam and that the deflection device (58) is arranged on a beam entry side (52) of the workpiece and so is designed so that the beam is deflected in an at least approximately horizontal direction (14b) (Fig. 3; Fig. 9). 13. Device according to claim 10, 11 or 12, characterized characterized in that a magnetic deflection device (58,58b) on a beam exit side (54) of the workpiece is arranged, which deflects the beam in a relative to the horizontal obliquely upward direction. 809850/0834 14. The device of claim 10, wherein the beam is substantially is directed vertically downwards on the workpiece, penetrates the workpiece and at a beam exit surface of the workpiece from this exits, characterized in that a magnetic deflection device on the beam exit surface (54) (58 ") is arranged, which deflects the beam to the horizontal. 15. Device according to claim 14, characterized by a device (58a) for compensating for a part of the deflection field (68 ¹ ) generated by the deflection device (58 ") that is further away from the beam exit surface (54). 16. Device according to claim 13 or 14, characterized characterized in that an additional electromagnetic device (82,84,86,88,92, 94) is provided in order to deflect the beam periodically transversely to a central beam axis (FIGS. 25 to 27). 17. Device according to at least one of claims 10 to 16, characterized in that a weld pool support device on the beam entry side (52) (18) is arranged, which has a trough of relatively low thermal conductivity for receiving melt (12) from the Welding zone, as well as a cooling zone (B Fig. 6) relatively high thermal conductivity, which cools and solidifies the melt, contains (Fig. 5 to 8). 18. Device according to claim 17, characterized in that that the cooling zone (B) has a channel (40) tapering in cross section for forming a weld bead (42) from the contains solidifying melt (12). 809850/0834 -υ- 19. Device according to claim 17 or 18, d a d u rc ti characterized in that the trough is provided with an insert (32) made of a refractory material of low thermal conductivity is formed. 20. Device according to claim 17, 18 · or 19, d a d u r ch marked that the weld pool support device from a holder (34) movable with the beam with respect to the workpiece. 809850/0834